The invention relates to an annular seal consisting of a reinforcing member and an annularly constructed lip member made of an elastomeric material fastened thereto.
Seals of this kind are used, for example, in the sealing of the passage of shafts through housing walls. They consist usually of a reinforcing member of metal having an angular profile, a lip of an elastomeric substance being vulcanized onto the inwardly extending leg of the profile. The manufacture of such seals consequently requires special production equipment and involves high initial investments.
The fact that the reinforcement is made of metal is not coincidental, but results instead from the need to use a material whose surface will enter into a firm bond with the lip in the vulcanization process. Hitherto, satisfactory results have not been achieved in the use of thermoplastics for the construction of the reinforcement unless adhesives are used.
German Auslegeschrift No. 2,312,548 discloses a radial shaft sealing ring in which the lip, made of an elastomer, is gripped between the two axially associated halves of the reinforcing ring. To achieve a fluid-tight joint between the two parts, the position of installation must be such that an axial compression constantly takes place. Another disadvantage of this radial shaft sealing ring is that it consists of three individual parts which must be manufactured independently of one another. This necessarily involves relatively high production costs.